First trimester biochemical screening for Down syndrome: free beta hCG versus intact hCG
- 13 October 2000
- journal article
- research article
- Published by Wiley in Prenatal Diagnosis
- Vol. 20 (10) , 785-789
- https://doi.org/10.1002/1097-0223(200010)20:10<785::aid-pd892>3.0.co;2-6
Abstract
To compare free beta hCG versus intact hCG in first trimester Down syndrome screening we analysed 63 cases of Down syndrome and 400 unaffected control pregnancies between 10 and 13 weeks' gestation. The Down syndrome median multiple of the median (MoM) was significantly higher (p=0.001) for free beta hCG (1.89 MoM) than for intact hCG (1.37 MoM). Although distributions for free beta hCG (unaffected, 0.2157; DS, 0.2322) are wider than for intact hCG (unaffected, 0.1697; DS, 0.2158), overall 27% of Down syndrome cases were above the 95th percentile for free beta hCG compared to 19% for intact hCG. Combined with maternal age, free beta hCG detected 45% of Down syndrome pregnancies at a 5% false positive rate. Intact hCG combined with maternal age demonstrated a detection efficiency comparable to maternal age alone (35% versus 32%). In contrast, a recent study (Haddow et al., 1998 —NEJM 338: 955–961) indicated that intact hCG yielded a higher first trimester Down syndrome detection efficiency than free beta hCG (29% versus 25% respectively). Re‐analysis of distribution parameters in the Haddow et al. study, however, show that free beta hCG was actually the better marker (23% detection for intact hCG versus 29% for free beta hCG). Copyright © 2000 John Wiley & Sons, Ltd.Keywords
This publication has 19 references indexed in Scilit:
- Early pregnancy screening for fetal aneuploidy with serum markers and nuchal translucencyPrenatal Diagnosis, 1999
- First-trimester screening for Down syndrome using nuchal translucency measurement with free β-hCG and PAPP-A between 10 and 13 weeks of pregnancy—the combined testPrenatal Diagnosis, 1999
- Screening of Maternal Serum for Fetal Down's Syndrome in the First TrimesterNew England Journal of Medicine, 1998
- First-trimester Down syndrome screening: Free β-human chorionic gonadotropin and pregnancy-associated plasma protein AAmerican Journal of Obstetrics and Gynecology, 1996
- Total amount of circulating human chorionic gonadotrophin α and β subunits in first trimester trisomies 21 and 18Journal of Endocrinology, 1996
- Maternal serum screening for Down's syndrome in the first trimester of pregnancyBJOG: An International Journal of Obstetrics and Gynaecology, 1995
- Maternal serum human chorionic gonadotrophin and pregnancy‐associated plasma protein a, markers for fetal down syndrome at 8–14 weeksPrenatal Diagnosis, 1994
- First‐trimester biochemical screening for fetal chromosome abnormalities and neural tube defectsPrenatal Diagnosis, 1993
- Maternal serum Down syndrome screening: Free β-protein is a more effective marker than human chorionic gonadotropinAmerican Journal of Obstetrics and Gynecology, 1990
- Abnormal maternal serum chorionic gonadotropin levels in pregnancies with fetal chromosome abnormalitiesPrenatal Diagnosis, 1987